Abstract: Effects of reference frame on cardinal direction judgments were tested by three experiments. Experiment 1 demonstrated that imaginary orientation of target object relative to reference object was one of factors contributed to cardinal direction judgments (CDJ). Experiment 2 indicated the patterns of camera heading and imaginary orientation effect on cardinal direction judgments can not be influenced in another cardinal direction task. Experiment 3 showed there existed large differences between two different types of cardinal direction judgments: CDJ based on judgment of two objects relative location is more difficult than CDJ based on camera heading judgment. For camera heading in all experiments, north-advantage effect and cardinal direction effect were found. For imaginary orientation, the pattern of process time was: front-back axis < right-left axis < others. The results were discussed by means of canonical axis and canonical direction.

Key words: cardinal direction judgments, environmental reference, egocentric reference, camera heading effect, imaginary orientation effect